Nagayama Gyoko, Zhang Dejian
Department of Mechanical Engineering, Kyushu Institute of Technology, Sensui 1-1, Tobata, Kitakyushu, Fukuoka 804-8550, Japan.
Soft Matter. 2020 Apr 14;16(14):3514-3521. doi: 10.1039/c9sm02513h. Epub 2020 Mar 26.
A general partial wetting model to describe an intermediate wetting state is proposed in this study to explain the deviations between the experimental results and classical theoretical wetting models for hydrophobic surfaces. We derived a theoretical partial wetting model for the static intermediate wetting state based on the thermodynamic energy minimization method. The contact angle based on the partial wetting model is a function of structural parameters and effective wetting ratio f, which agrees with the classical Wenzel and Cassie-Baxter models at f = 1 and 0, respectively. Si samples including porous surfaces, patterned surfaces and hierarchical nano/microstructured surfaces were prepared experimentally, having the same chemical composition but different physical morphology. We found that the experimental water contact angles deviate significantly from the classical Wenzel and Cassie-Baxter models but show good agreement with the proposed partial wetting model.
本研究提出了一个通用的部分润湿模型来描述中间润湿状态，以解释疏水表面实验结果与经典理论润湿模型之间的偏差。我们基于热力学能量最小化方法推导了静态中间润湿状态的理论部分润湿模型。基于部分润湿模型的接触角是结构参数和有效润湿率f的函数，分别在f = 1和f = 0时与经典的文泽尔模型和卡西-巴克斯特模型一致。通过实验制备了具有相同化学成分但不同物理形态的硅样品，包括多孔表面、图案化表面和分级纳米/微结构表面。我们发现，实验测得的水接触角与经典的文泽尔模型和卡西-巴克斯特模型有显著偏差，但与所提出的部分润湿模型吻合良好。
